Articular cartilage defects do not heal satisfactorily. Our preliminary work with electrochemical stimulation of articular cartilage defects supports the concept of an aborted potential for repair. Our results also indicate that small changes in the electrical micro- environment are capable of enhancing the repair response. Our objectives are to define the electrical parameters and techniques that will allow efficient, consistent and safe repair of mammalian articular cartilage defects with hyaline cartilage. Our methods include evaluation of surgically created defects in rabbits and naturally occurring defects in dogs and horses after periods of treatment with electrical devices. Evaluation techniques include light microscopy, transmission electron microscopy and scanning electron microscopy. Eventual clinical application is anticipated. BIBLIOGRAPHIC REFERENCES: Baker, B.E.; Spadaro, J.; Marino, A.; Becker, R.O. The Electrical Stimulation of Articular Cartilage Regeneration, Annals of the New York Academy of Sciences, 238:491-499, Oct. 11, 1974.